Impulse or ratchet relay



Y A L E R @cfg. 25,, 1955 Filed Oct. 25, 1954 INVENTOR. Haber! fC. C/zeliz BY A TT Y5 United States Patent IMPULSE QR RATQHET RELAY Robert K. Cheltz, Hamilton, Ohio lApplication October 25, 1954, Serial No. 464,319

6 Claims. (Cl. 260-105) This invention relates to impulse or ratchet relays and has for an object the provision of a device that is sturdy, vcompact and economical in construction, is. reliable in operation, and which is arranged to be easily modified by the installing electrician on the job for operation on either the opening or the closing of a circuit through its single solenoid coil.

Another object of the invention is to provide a device that is adaptable for the control of several electrical devices that are to be alternately energized.

Still another object of the invention is to provide a de vice that is suitable for many and varied uses in control circuit installations so that such installations are simplified and employ a minimum number of relays each of which includes its own precision switches which also cooperate in the control of the associated relay.

A further object of the invention is to provide an improved ratchet mechanism for devices of this type.

prior to the completion of the armature rise following the subsequent closing of an electrical circuit through the solenoid coil.

Fig. 4 is a cross sectional elevational view showing the combined ratchet, detent and cam element of the device mounted in end for end reversed position in the device for eifecting the switching operation at the instant of the completion of an electrical circuit through the solenoid.

In modern plant operation in industry automatic electrical control systems include wide varieties or" arrangements to insure automatic sequences of circuit closing operations for various purposes and these have in the past often involved complications in circuit layoutand in the selection of devices included therein for automatic control purposes. By the devices of the invention many problems in the art are greatly simplified and the number of relays employed in a given installation may frequently be reduced without sacrifice of efiiciency of the involved installation. In plant installations where duplicate electrical devices such as pumps or compressors are provided to assure continuous service operation the impulse relay of the invention lends itself to the operation ofsuch devices in alternation following successive interruptions to electrical supply so that neither of the electrically .drivenpumps or compressors are. permitted to remain idle over long periods of time as merely stand-by equipment.

In the device as shown in thedrawings a suitable sole- ICC 'noid 5 has removablyimounted on the:top thereof a pair zontal plane on the top ofsolenoid 5. .A suitable cover member (not shown). may be provided to close the open top and ends of the closurespace between the side walls 6 and 7.

The perforated brackets. 11 on the .solenoid 5 may be used to supportthe entire. device in any known manner on a wall or the like,,and the device is preferably positioned to permit vertical rise andlfall of the armature 12 through the bottom of the core and coil assembly 13 of the solenoid. Armature 12 has an upstanding rigid tongue 14 on the upper end which may pass through an opening formed by notches 15 in the abutting edges of the bottom flanges 8. A headed stud16 has a shouldered reduced end 17 screwed into the tongue 14 nearthe top and the head of the stud may descend to contact a stop 18 on top of the soienoid core to provide a definite limit to the fall of armature 12. A fixed stud 19 on the solenoid frame supports a spring 20, the opposite ends of which are engaged on the solenoid frame andtne armature respectively for yieldably urging the latter to the aforesaid lower limit stop. while the lower end of armature 12 has lateral extensions 21 or equivalent means to engage the solenoid core provide an upper limit to the rise of thearmature.

A stiif metal ratchet pawl 22 has near its lower end a hole 23 through which the shank of stud 16 passes freely to connect the pawlto tongue 14 on the armature. A light ,coil spring 24 encircles the shank of the stud and has its opposite ends abutting the head of the stud and the outer face of said pawl 14, to yieldably hold the adjacent overlapping faces of the tongue and pawl in fiatwise abutment. .The pawl 22 has a guide finger 25, which may be struck from the body of the pawl as shown, said finger 25 extending through an open topped guide slot 26 formed in the top end of armature tongue 14 to hold the pawl against sidewise tilting movement in the direction of either of the side walls 6 or 7 but permitting inclination of the abutting face of said pawl on the adjacent transverse corner edge 27 at the top of tongue 14 as a fulcrum, and against the yielding resistance ofspring. 24.

The free upper end of pawl 22 has an integral pawl hook 28 with a short downwardly beveled free edge 29.

:The bottom face 30 of the hook 28 isfiat and is slightly inclined downwardly toward the free edge, and the major portion 31 of the top face of said hook is flat and approximately parallel to bottom face 3a).

A combined ratchet, detent and cam wheel indicated generally as 32 has a shaft 33 extending through both ends thereof and fixed for rotation with ,it in any suitable manner as by a set screw 34. The shaft is shouldered to provide short reduced ends 35 which are journalled for rotation in aligned; bores 36 in side walls 6 and 7. The combination wheel-32 comprises a central ratchet wheel section 3'7 with hubs-:38, at each sidethereof and cam and detent discs '39 and 40 on the outer ends of the respective hubs.

,Ratchetsection37 in;the present embodimenthas eight ratchet teeth 41 each having its plane flat breast 42 meet ingits flat.plane top143 atan-acuteangleto provide a transverse tooth edge=44 (see -F ig; 4). As, can be best peripheral detent notches 45 and between adjacent notches 45 are peripheralcam. Portions 46. The disc 40 is formed-with notches 47 and cam portions 48 so arranged that each notch 47 is centered opposite the center of a cam 46 on the companion disc 39.

As shown in Fig. 2 the shaft 33 is mounted forwardly of the travel line of pawl 22 and at a level midway the that pass through the existing fastener receiving holes in said switches and through the side walls 6 and 7. The said switches together form a spacer against which the said side walls are secured in parallelism by said bolts. The roller arm actuators 51 and 52 forming parts of switches 48 and 49 are spring urged downwardly away from the lower faces of the switches to a normal open circuit position and the switches are so located relative to the rotary member 32 as to permit the roller 53 on arm 51 to rest on the top of a cam rise 46 of cam disc 40 for closing switch 48, while the roller 54 on arm 52 is spring urged into fully seated relation in a detent notch 45 in cam disc 39 thus placing switch 49 in open circuit condition and at the same time holding the member 32 against accidental movement.

When member 32 in rotated 45 the roller 54 is moved out of notch 45 in disc 39 and onto cam rise 46 on said disc thus closing switch 49, and at the same time roller 53 moves off of cam rise 48 on disc 40 and into notch 47 for opening switch 48 and also for holding the member 32 in the advanced position.

It will be noted in Fig. 2 that the breast 42 of the ratchet teeth 41 adjacent the pawl hook 28 are faced upwardly and that the mid-length of each tooth is opposite the center of a diiferent one of notches 45 and 47 on the several cam discs. The travel distance of the pawl hook 228 is not appreciably greater than the length of a ratchet tooth 41 so that lost motion in the operation of the device is avoided and reliable, quick responsive action results. When armature 12 is at its lower limit the bottom face 30 of pawl hook 28 overhangs the breast 42 of a ratchet tooth and the edge 29 is at the juncture of the breast of such tooth and the lower end of the top face 43 of the next tooth above. When the solenoid is next energized (see Fig. 3) the upward movement of armature 12 pushes pawl 22 upward and the edge 29 of the pawl hook slides up along the outwardly inclined face of the top 43 of the tooth and in doing so tilts the stiff pawl 22, about the edge 27 of tongue 14 as a fulcrum, against the yielding resistance of spring 24 until the edge 29 reaches and passes over the edge of the ratchet tooth. Then the flat bottom face 30 slides onto the breast 43 of the ratchet tooth under the pressure of spring 24 against the lower end of the pawl.

The pawl hook 28 remains in positive engagement with the ratchet tooth so long as the armature remains elevated by continued energization of solenoid coil 130. During this operation switches 48 and 49 have remained in their respective closed and open circuit conditions because the member 32 remained stationary during the up-stroke of pawl 22, and the roller 54 of the open switch 49 in a notch 45 in cam disc 39 served as holding detent to prevent movement of the member 32.

However at the instant the armature coil 130 becomes de-energized, the armature 12 drops by gravity and with the aid of spring 20 to pull pawl 22 down thus advancing member 32 through 45 and reversing the condition of switches 48 and 49. In its descent the pawl 22 remains substantially vertical and in parallelism with the tongue 14.

The device is of course adapted for a wide variety of uses in either simple or relatively complex control systems. In simpler automatic control circuits the solenoid coil 130 may be wired in series parallel with the switches 48 and 49 and all of them subject to response to a switch say of the pressure type or of float controlled type or any other switch that may be required for a given electrical control layout.

The switch changing impulse is generally desired at the moment of breaking the circuit through solenoid coil as previously described. It is of course not uncommon for an automatic electrical control layout to include a number of ratchet relays and often different types of such devices are required.

The device of the present invention is arranged and adapted for quick and easy end for end reversal of member 32 by the installing electrician on the job in order to cause the switch change over impulse to occur at the instant the solenoid coil 13% is energized instead of as previously described. This conversion involves only the loosening of through-bolts 5i and screws 9 to enable the side walls 6 and 7 to be slightly spread apart and the member 32 with its shaft can then be removed and turned end for end and replaced in the bearing bores in said members 6 and 7. Before tightening the screws 9, a shim 55 or equivalent of about the thickness of the pawl tongue 23 is interposed between flanges 53 and 10, so that the arrangement is as shown in Fig. 4 wherein the breasts of the ratchet teeth face downwardiy and the member 32 has been raised to allow the point 44 of a ratchet tooth to rest on the top flat face 31'of pawl hook 28 when the armature has dropped due to the de-energized condition of solenoid 5. Under this arrangement the pawl effects a vertical upward thrust when the solenoid is energized and pushes the tooth to turn the member 32 counterclockwise and the pawl remains elevated to assist in holding member 32 in position. Cam discs 39 and 40 being alike will co-act with rollers 54 and 53 respectively which rollers effect alternate opening and closing of the associated switches.

When the armature drops and lowers the pawl, the hook is cammed outwardly as it rides down the top of the ratchet tooth and then moves beneath the breast of the tooth to the position shown in Fig. 4.

The ratchet relays of the invention are unusually easy to adapt to endless arrangements in automatic control systems, and they utilize a minimum of sturdy and inexpensive parts in compact and reliable arrangement. The invention herein is not to be understood as limited to the specific number of switches shown nor to the specific angular relation of the switches to the pawl since these may be modified according to the teachings of this invention and within the scope of the appended claims.

What is claimed is:

1. In an impulse ratchet relay the combination of a pair of side walls, a combination member comprising a ratchet toothed portion and a plurality of cam and detent discs mounted fixedly on a shaft, said member having its shaft journalled at its opposite ends in said side walls, precision switches mounted between the side walls and having actuating roller arms cooperating respectively with the several discs whereby each switch is alternately closed and opened on rotational advance of said member, a solenoid member including brackets removably connected to the bottoms of said side walls and a vertically operating armature having a tongue projecting upwardly between said side walls, a headed stud secured in the armature tongue, a still pawl member having a pawl hook for engaging the ratchet teeth on the combination member, said pawl having a bore therethrough for connecting it with the stud and permitting limited fulcrurned tilting about the top edge of said armature tongue, said tongue having a vertical slot in the top thereof, a projecting lug on the pawl extending into said slot for permitting rocking movement of the pawl toward and away from the ratchet teeth and precluding rocking of the pawl toward the side walls and a spring on the stud yieldably urging the lower end of the pawl into fiatwise abutment on the adjacent face of the armature tongue.

2. The combination as set forth in claim 1 characterized by the fact that said side walls are separable to permit end for end reversal of the combination member and its shaft for selectively arranging for clockwise advancement of the combination member as the armature and pawl descend on de-energization of the solenoid or for counter-clockwise advancement of the combination member as the armature and pawl are lifted by energization of said solenoid.

3. The combination as set forth in claim 1, characterized by the fact that the cam discs are similar in form and have the cam rises of one of them opposite the notches in the other.

4. The combination as set forth in claim 2 wherein the pawl hook is beveled near its edge and has a flat top for upward thrust on the point of a ratchet tooth when the combination member is mounted in one position and said pawl tooth has a fiat bottom face for exerting a downward pull on a ratchet tooth when said combination member is mounted in a relatively end for end reversed position.

5. In a device of the class described the combination of a solenoid having a vertically movable armature and having brackets at the top, a pair of side walls having inturned bottom flanges seating on said solenoid brackets, releasable means to secure the flanges rigidly to the brackets and permit limited spreading of the walls from each other, said walls having opposed aligned bores, a combination member having an axial shaft fixed therein, said shaft removably journalled in the bores in said walls to permit end for end reversal of the combination member in its mounting, said member including spaced cam discs and an intermediate toothed ratchet wheel, a rigid pawl yieldably connected at its bottom with the solenoid armature, said pawl having a bevel edge hook contacting said ratchet wheel and adapted to ride over the top of a ratchet tooth on movement of the pawl and armature in one direction, said pawl hook being selectively engagable with the breast and point of a ratchet tooth for moving the combination member in one of a selected clockwise or counter-clockwise direction depending on the disposition of said member in its journalled mounting between said walls.

6. The combination as set forth in claim 5 characterized by the fact that shims approximating the thickness of the pawl book are removably interposed between the bottom flanges of said walls and the solenoid brackets to slightly elevate the combination member for positive counter-clockwise movement thereof by said pawl.

No references cited. 

